CV Joints

Teresa Aquila, a renowned mechanic, columnist, teacher and a producer of an auto repair video for woman. Her mechanical career has spanned 41 years working on everything from Porsches to Heavy Equipment to including classic vehicles which she owns several and has personally restored in a world dominated by men.

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What’s That Noise In My Front End?
Have you ever been driving and started to make a turn either to the left or right and all of a sudden you hear this clicking noise? Maybe you even hear a whining sound as you travel down the road wondering what the heck that is. The first thing on your mind is “how much is this going to cost me”?

When front wheel drive cars were introduced, the axles moved from the rear end of the car to the front coming straight out of the transmission. As you can see in the photo, the outer ends of the CV (constant velocity) Joints are made up of a rubber boot. The boot covers the joint itself and needs constant grease, so within the boot it’s packed with grease to keep the joint cool and lubricated. So as the axle turns the grease in continually being tossed around inside the boot.

EXPLODED VIEW OF A CV JOINT

Over time the boot takes quite a bit of wear. As the vehicle turns, the boot stretches and wears when it is packed with snow during winter conditions and very hot during some temperatures. It is constantly working hard to keep your tires rolling down the road. So what does all this mean, well rubber breaks down in time causing it to split or crack.

Remember that grease inside the boot, when it breaks or cracks guess where the grease goes? Yes it ends up all over the area around the boot and on the inside of the wheel and once the grease has been removed, then the Joint begins to wear due to lack of lubrication and that is the noise you hear, the joint metal to metal.

CV JOINT BOOT THAT CAME APART

So how can this be prevented, well keeping the area clean by steam cleaning or hosing off the area after driving in dirt conditions. Years ago the early mechanics would perform a rubber lube meaning they would treat all the rubber parts underneath the car. That is not true today, but it can help to keep the rubber pliable by treating it. When you get your oil changed ask your mechanic to check the boots so you’ll have an idea on its condition periodically. Or locate them on your vehicle and give it a glance every so often. If you have your oil changed at a Quick Lube shop, most of the employees performing the service are probably not aware of what to look for or know how to treat it. Your mechanic would be the one I’d ask.

Now if the CV Joint does fail there is more to it than just replacing it. Many components need to be removed in order to access them. Not complicated, just something to be aware of. Some vehicles may need an alignment once replaced; it will depend on the make. The CJ Joints themselves are not expensive; the labor is what will cost you here. Some aftermarket companies offer a replacement boot but I highly do not recommend them. Trying to get the boot to seal is messy and tricky not to mention it could come apart again.

Another thing to remember is try to remember not to make really hard sharp turns all the time this will cause the boot to have excessive stretching. If the CV Joint failure goes unnoticed or repaired and it happens to your car, do not put is off very long, it will cause the axle to lock up and could cause an accident. It could break apart not allowing you to having steering on one wheel making the driver to lose control. Safety is key, so do your proper maintenance and your driving experience will always be a pleasant one.